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Autonomic Nervous System Function (autonomic + nervous_system_function)
Selected AbstractsAutonomic nervous system functions in children with breath-holding spells and effects of iron deficiencyACTA PAEDIATRICA, Issue 9 2005Abdülkerim Kolkiran Abstract Aim: To analyse the activity of the autonomic nervous system during breath-holding spells, we assessed the ECG changes, including ventricular repolarization parameters before and during the spell. We also analysed the effects of iron deficiency on these ECG parameters. Methods: The study group consisted of 37 children with breath-holding spells (30 cyanotic, 7 pallid) (mean age±SD: 12.9±10.8 mo). Twenty-six healthy children (mean age±SD: 14.4±8.6 mo) served as a control group. All patients and controls had standard 12-lead simultaneous surface ECG. All patients had ECG recordings during at least one severe breath-holding spell obtained by "event recorder". Traces obtained by "event recorder" were analysed in terms of mean heart rate and the frequency and duration of asystole during the spell. Results: Respiratory sinus arrhythmia on standard ECGs and asystole frequency during spells were higher in patients with pallid breath-holding spells. Patients with iron deficiency had a lower frequency of respiratory sinus arrhythmia and prolonged asystole time during the spell. There was no difference in terms of ventricular repolarization parameters (QT/QTc intervals and QT/QTc dispersions) between patients and controls and between patient subgroups (cyanotic versus pallid). Conclusion: These results confirmed the presence of autonomic dysregulation in children with breath-holding spells. Iron deficiency may have an impact on this autonomic dysregulation. Ventricular repolarization was unaffected in patients with breath-holding spells. [source] Effects of alcohol and smoking during pregnancy on infant autonomic controlDEVELOPMENTAL PSYCHOBIOLOGY, Issue 3 2009William P. Fifer Abstract Prenatal exposure to smoking and alcohol increases the risk for Sudden Infant Death Syndrome (SIDS). Physiological changes associated with these exposures are not well studied. Full-term infants were tested within the first 3 days of life. We hypothesized that maternal alcohol consumption and/or smoking during pregnancy would alter autonomic nervous system function. Newborns whose mothers smoked during pregnancy had lower beat-to-beat heart rate variability in quiet sleep. Infants whose mothers consumed alcohol had lower global heart rate variability, but only in active sleep. Unexposed infants demonstrated increases in heart rate with head-up tilt and decreases in heart rate with head-down tilt, but smoking and alcohol-exposed infants showed no significant responses. These results indicate that autonomic function is altered by prenatal exposure to alcohol and smoking. Such markers may provide early identification of infants at greatest risk for SIDS. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 234,242, 2009 [source] QT Interval Dispersion and Cardiac Sympathovagal Balance Shift in Rats With Acute Ethanol WithdrawalALCOHOLISM, Issue 2 2010Seiko Shirafuji Background:, Dysregulation of autonomic nervous system function and impaired homogeneity of myocardial repolarization are 2 important mechanisms for the genesis of ventricular arrhythmias in nonalcoholic subjects. Our previous study suggested that acute ethanol withdrawal promoted the shift of cardiac sympathovagal balance toward sympathetic predominance and reduced the vagal tone, which were related to a higher incidence of ventricular arrhythmia and related death. However, the homogeneity of myocardial repolarization and its relation with the cardiac sympathovagal balance are unknown, especially in alcoholic subjects. The aim of the present study was to clarify these points. Methods:, Male Wistar rats were treated with a continuous ethanol liquid diet for 49 days, and then subjected to 1-day withdrawal and 1-day withdrawal with 7-day carvedilol (can block the sympathetic nervous system completely via ,1, ,2, and , adrenergic receptors) pretreatment. The cardiac sympathovagal balance and homogeneity of myocardial repolarization were evaluated based on the heart rate variability (HRV) and QT interval dispersion (QTd: dynamic changes in QT interval duration). Results:, The increase in QTd was observed only in rats at 1-day withdrawal, but not in nonalcoholic, continuous ethanol intake, and 1-day withdrawal with 7-day carvedilol pretreatment rats. At 1-day withdrawal, the low-frequency power/high-frequency power (LF/HF) ratio in HRV was elevated and correlated with the QTd. The increased QTd and elevated LF/HF ratio were normalized by the 7-day carvedilol pretreatment in rats at 1-day ethanol withdrawal. Conclusions:, In rats with an abrupt termination of the chronic continuous ethanol intake, the homogeneity of myocardial repolarization impaired and correlated with the cardiac sympathovagal balance. Carvedilol pretreatment is associated with a reduction in both the QTd and LF/HF ratio, raising the possibility that the cardiac sympathovagal balance shift may be responsible for the impaired homogeneity of myocardial repolarization, and that ,-blocker pretreatment may decrease the mortality risk during alcoholic withdrawal. [source] Orthostatic heart rate variability analysis in idiopathic Parkinson's diseaseACTA NEUROLOGICA SCANDINAVICA, Issue 5 2006E. Mihci Objectives ,, We evaluated time and spectral analyses of 24-h heart rate variability (HRV) and the heart rate responses to passive tilt in patients with idiopathic Parkinson's disease (IPD) in order to investigate cardiovascular autonomic functions. Material and methods ,, Twenty-three subjects with IPD without autonomic symptoms and 15 age-matched healthy controls were enrolled. Frequency- and time-domain HRV parameters were studied during resting and passive head-up tilt (HUT) test. Results ,, All time-domain parameters were found to be low in patients with IPD. In patients with IPD, both low frequency (LF) and high frequency (HF) decreased during HUT period and no significant change in LF to HF ratio was noted. Both time- and frequency-domain HRV indices showed no correlation with age, disease severity and duration, and with l -dopa medication. Conclusion ,, The results indicate that impairment of autonomic nervous system function in IPD without autonomic symptoms is frequent, and does not show clear association with clinical stage and the age of the patients. [source] Cardiovascular Regulation through Hypothalamic GABAA Receptors in a Genetic Absence Epilepsy Model in RatEPILEPSIA, Issue 2 2002Rezzan Gülhan Aker Summary: ,Purpose: ,-Aminobutyric acid (GABA) plays a vital role in both central cardiovascular homeostasis and pathogenesis of epilepsy. Epilepsy affects autonomic nervous system functions. In this study, we aimed to clarify the role of GABAA receptors in hypothalamic cardiovascular regulation in a genetically determined animal model of absence epilepsy. Methods: Nonepileptic Wistar rats and genetic absence epilepsy rats from Strasbourg (GAERS) were instrumented with a guide cannula for drug injection and extradural electrodes for EEG recording. After a recovery period, iliac arterial catheters were inserted for direct measurement of mean arterial pressure and heart rate. Bicuculline, a GABAA -receptor antagonist, was injected into the dorsomedial (DMH) or posterior (PH) hypothalamic nuclei of nonepileptic control rats or GAERS. Blood pressure, heart rate, and EEG recordings were performed in conscious unrestrained animals. Results: Bicuculline injections into the hypothalamus produced increases in blood pressure and heart rate of both control rats and GAERS. The DMH group of GAERS showed a twofold increase in the blood pressure and the heart rate compared with those of control rats. Pressor responses to bicuculline, when microinjected into the PH, were similar in the nonepileptic animals and GAERS. Conversely, the amplitude of tachycardic responses to the administration of bicuculline into the PH was significantly higher in GAERS compared with those of control rats. Conclusions: The bicuculline-induced increases in blood pressure and heart rate were more prominent when given in the DMH of GAERS. These results indicate an increased GABAA receptor,mediated cardiovascular response through the DMH in conscious rats with absence epilepsy. [source] | ||||||||||